hi Lexwater
just calculate up to what height of the tank volume you would get 500000 gallons. simply place the feeder pipes up to that height. ussually there is free board if 1 to 1.5 feet left in the tank
regards
Rajeevalochana HN
the usage of GI pipes is not that arbitary in India as some of the member have said. the available site conditions guide the usage of material in the rising/distribution mains. they may underlying strata which may be rocky.in Many of the places the in southern India the rock strata may be mat at...